Imager-Based Optical Code Reader Using Fixed Mirrors
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Solution Overview
Problem
Laser-based bar code readers are complex, costly, and unreliable due to moving parts, particularly the motor and laser illumination source, which affects their performance and reliability in reading optical codes at various locations and orientations.
Innovation Solution
An imager-based optical code reader system that mimics the performance of laser-based scanners without moving parts by using a camera to capture multiple thin strip-shaped views from different perspectives, creating a composite image with a set of fixed mirrors to achieve perspective diversity and decode optical codes effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If laser-based scanners are used to read optical codes, then code reading capability is achieved, but device complexity and cost increase due to moving parts
Solution Approach 1:
The patent replaces the mechanical laser scanning system with a stationary imager-based system. Instead of using a laser beam that physically scans across the code with moving mirrors and motors, the system uses a fixed imager to capture the entire code field of view simultaneously. This eliminates all mechanical moving parts while maintaining the ability to read optical codes through digital image processing.
Solution Approach 2:
The patent creates a digital copy of the optical code through the imager's sensor array. Rather than physically scanning the code with a laser spot, the system captures a complete optical image of the code and processes this digital representation. This allows the code information to be copied and analyzed without any mechanical interaction with the physical code.
2Measurement precision
If laser illumination source is used, then code reading performance is improved, but power consumption and reliability issues arise
Solution Approach 1:
The patent replaces the active laser illumination source with a passive imaging approach. Instead of projecting a laser beam and measuring reflected light, the system uses the imager's sensor to directly detect the optical code in the ambient field of view. This eliminates the high power consumption associated with laser diodes and their control circuitry.
Solution Approach 2:
The patent substitutes the expensive, power-intensive laser illumination system with a simpler, lower-cost imager sensor. The imager consumes significantly less power and has no moving parts or illumination sources that require maintenance or replacement, effectively replacing a complex active system with a simpler passive detection system.
3Reliability
If moving parts are eliminated, then reliability improves, but achieving perspective diversity becomes difficult
Solution Approach 1:
The patent transitions from the temporal dimension of scanning (where a laser spot moves sequentially across the code over time) to the spatial dimension of simultaneous imaging (where the entire code is captured in a single static frame). The imager's two-dimensional sensor array captures all code information simultaneously across the field of view, eliminating the need for temporal scanning while maintaining complete code detection capability.
Solution Approach 2:
The patent makes the stationary imager perform multiple functions that were previously required separate mechanical components. The single fixed imager simultaneously captures the entire code field of view, provides perspective information through image processing, and enables code detection without requiring any moving parts. This universal approach replaces the specialized laser scanning function with a more versatile imaging system.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The imager-based system provides reliable and efficient code reading with reduced complexity, cost, and power consumption, achieving comparable performance to laser-based scanners in terms of perspective diversity and reliability, while eliminating the need for moving parts.
Implementation Method 1
An optical detector measures the intensity of the returned light as a function of time or position
Data Source
AI summary
Various improved imager-based optical code readers and associated methods are disclosed herein. According to one embodiment, an imager-based method reads an optical code (which may be, for example, a linear optical code such as a bar code) on an object in a viewing volume. The method comprises dividing an image plane into a plurality of strip-shaped sections, viewing the object in the viewing volume from a plurality of perspectives, forming a plurality of strip-shaped images corresponding to the plurality of perspectives, respectively, thereby creating a composite image containing data from a plurality of perspectives, and processing at least a portion of the composite image so as to ascertain the information encoded in the optical code on the object in the viewing volume. Certain embodiments can mimic the performance of a laser-based scanner without a laser or moving parts but instead utilizing an electronic imaging device such as an imager.